Various expressions and phrases we get from school can be entirely different from the real-world English used by native speakers. Hello, yes, no, because, thank you, I think, are words or phrases that are often used in a dialogue/conversation. If you want your dialogue to sound like a native speaker, you may try to use expressions instead of repeating the same responses many times.
Instead of saying “Yes” you can say:
- Sure, I will.
- Of course.
- No problem.
- Absolutely
- definitely
- OK
- You bet.
- Alright
- Why not?
Instead of saying “No” you can say:
- I’d love to, but I can’t.
- I wish I could make it work.
- Maybe another time.
- I’m sorry, I’m busy
- No way
- Etc.
